In a workflow, work items—be they physical items like products and paper documents or virtual items like communications and electronic documents—progress through one or more steps of processing each performed by resources, e.g., workmen, machines, agents, that are allocated in whole or in part to those stages. Representative workflows include call centers and assembly lines.
Traditional call-center resource and work-item selection algorithms have been limited by the call-center model presented by the automatic call distribution (ACD) switch. These conventional workflows generally employ a first-in, first-out (FIFO) selection algorithm at each state: the first available resource handles the first available work item. While variations on this basic algorithm have been developed over time, the underlying algorithm remains the same. For example, one known ACD switch represents resources as having skills and skill levels, and provides multi-priority queues for queuing work items to wait for resources with corresponding skills to become available. So any algorithms that are applied to this model are constrained by its limited and fixed structure. This conventional approach handles simple deviations from the underlying FIFO selection principle. But it quickly becomes unwieldy when used to implement a complex or flexible selection algorithm such as may be needed to select a “best” work item for the “best” resource. The limitations of this conventional approach become evident when one considers the example of an insurance company that sells three types of insurance, each one of whose agents must be licensed to sell each of these types of insurance on a state-by-state basis, and whose call center allows callers to select English-speaking or Spanish-speaking agents. This results in 300 possible combinations of skill requirements. Administering the conventional ACD switch for all of these combinations would be difficult if not impossible.